CVE-2021-3929
What it is
A DMA reentrancy issue was found in the NVM Express Controller (NVME) emulation in QEMU. This CVE is similar to CVE-2021-3750 and, just like it, when the reentrancy write triggers the reset function nvme_ctrl_reset(), data structs will be freed leading to a use-after-free issue. A malicious guest could use this flaw to crash the QEMU process on the host, resulting in a denial of service condition or, potentially, executing arbitrary code within the context of the QEMU process on the host.
At a glance
- Exploitability
- Can be exploited locally on the machine with an admin-level account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.7% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.7% in the next 30 days (EPSS).
- Severity: 8.2 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.7% · EPSS, next 30 days
- Weakness
- CWE-416 · Use after free
- Record status
- Modified
Affected
- Qemu < 7.0.0
- Fedoraproject Fedora 35
- Fedoraproject Fedora 36
Attack profile CVSS 3.1 · 8.2
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- High
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2021-3929.md and follow it. Check whether this project is affected by CVE-2021-3929. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://bugzilla.redhat.com/show_bug.cgi?id=2020298
- https://gitlab.com/qemu-project/qemu/-/commit/736b01642d85be832385
- https://gitlab.com/qemu-project/qemu/-/issues/782
- https://bugzilla.redhat.com/show_bug.cgi?id=2020298
- https://gitlab.com/qemu-project/qemu/-/commit/736b01642d85be832385
- https://gitlab.com/qemu-project/qemu/-/issues/782
References
- https://access.redhat.com/security/cve/CVE-2021-3929
- https://bugzilla.redhat.com/show_bug.cgi?id=2020298
- https://gitlab.com/qemu-project/qemu/-/commit/736b01642d85be832385
- https://gitlab.com/qemu-project/qemu/-/issues/556
- https://gitlab.com/qemu-project/qemu/-/issues/782
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XHNN7QJCEQH7AQG5AQP2GEFAQE6K635I/
- https://access.redhat.com/security/cve/CVE-2021-3929
- https://bugzilla.redhat.com/show_bug.cgi?id=2020298
- https://gitlab.com/qemu-project/qemu/-/commit/736b01642d85be832385
- https://gitlab.com/qemu-project/qemu/-/issues/556
- https://gitlab.com/qemu-project/qemu/-/issues/782
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XHNN7QJCEQH7AQG5AQP2GEFAQE6K635I/
- https://security.netapp.com/advisory/ntap-20250228-0010/